A blog about random things and sometimes about my work translating and developing KDE and anything

Tuesday, November 09, 2010

My CPU fan does not speedup

Dead Lazyweb: I'm having problems because the fan of my laptop seems to always be on "slow mode" and my CPU is getting to 80/90 ºC and sometimes the laptop just shut downs itself. I know the fan can spin faster because in those cases the laptop shut downs, upon reboot the fan makes more noise while booting, but once it gets to Linux it turns to that slow mode again. Any idea how do i make it smart so that it actually goes faster when the CPU temperature raises?

12 comments:

In my desktop at least fanspeed is controlled by bios, you could check if it's the os by booting a live cd maybe?Also as ian monroe said it'd be a good idea to clean the fan too. just a bit of pressured air through the holes in the case should be enough

I'd begin by doing the cleaning others have advised but next I'd move to checking that the CPU temperature is being properly sensed via an install of lm_sensors / lm-sensors package.

sudo apt-get install lm-sensors

To configure the sensors do:

sudo sensors-detect

You will be offered a very detailed diagnostic showing what drivers may be needed to get sensors to work and many, many other details...do what is advised, if anything, to get the sensors working or just load the lot using:

modprobe coretempmodprobe i2c-i801

Now try reading the sensors output using:

sensors

(meaning type the above as a shell prompt command)

That should get you a bit closer to finding out what is going on...for further details try:

It could just be a hardware problem. For example all 3 Thinkpads I ever owned had this issue at some point. Sent them in for repairs and they all came back with the note saying that the heat-sink assembly was replaced.

Apparently after a while the thermal paste that ensures good contact between the CPU/GPU starts to deteriorate and there is nothing you can do about it.

I wouldn´t install Windows 7. On every benchmark i ever seen and on every test on my Notebook with Windows 7 my CPU Usage and so battery usage is much higher and so the battery lasts for a much shorter time.

What distro are you using? I would recommend go to the IRC Channel of your distro and check how the kernel is build and what you can do.

Given that the fan isn't revving up, it's probably not 'just crud', though cleaning isn't a bad idea. Before you start feeding your kernel boot parameters I'd suggest searching your distribution's package names for a 'laptop' meta package of some sort, packages that have your '$PROCESSOR' in the name, and the name and decryption in the package archive for your '$BRAND' of laptop (but probably not the model number).

I have the same problem with my Thinkpad x201 running Kubuntu. The problem did not appear in Lucid, but it does in Maverick. I believe it may be related to Graphics, because it happens when I do Video encoding or watch movies even though the CPU is far from 100%. So far my solution is simple: Remove the battery and CPU temp is about 20 C lower.